Meaning Of A Tag: A collaborative approach to bridge the gap between tagging and Linked Data

Transcription

1 Meaning Of A Tag: A collaborative approach to bridge the gap between tagging and Linked Data Alexandre Passant 1,2 & Philippe Laublet 2 1 Electricité de France R&D, Clamart, France 2 LaLIC, Université Paris-Sorbonne, France 1

2 Tagging is widely used but «A folksonomy represents simultaneously some of the best and worst in the organization of information» Adam Mathes (2004) Ambiguity A single tag can refer to various concepts Acronyms, ambiguous names Paris - City or People? SWIG - Semantic Web or C++? Heterogeneity Different tags can refer to the same concept Case-variation, synonymy, internationalization Beijing, Pekin - The same city SemanticWeb, SemWeb, SW - The same technology Lack of organisation No relationship between tags SemWeb, RDF, SPARQL - How to find one tag from another? 2

3 lacks of semantics Tags are just keywords They do not care any machine-readable information Computers cannot understand what the users have in mind when tagging content 3

4 Tags and the Semantic Web The Tag Ontology provides a way to represent tags and tagging actions in the Semantic Web tags:tag rdfs:subclassof skos:concept tags:tagging and tags:restrictedtagging SCOT - Social Semantic Cloud Of Tags - provides a way to model and share tagclouds between social tagging websites scot:tagcloud sioc:taggingactivity tags:tagging scot:tag scot:cooccurs_in scot:cooccurence But what about the meaning of tags? «When I tag this blog post Paris, I mean the French city» This is what MOAT is about 4

5 MOAT - Meaning Of A Tag MOAT - MOAT aims to provide An ontology to represent global and local meaning of tags in a machine-understandable way, using URIs of LOD resources to define those meanings A framework to assign and share meanings to tags in a collaborative and open way A way to let tags embeds themselves their semantic A process to create Linked Data from simple tagging actions 5

6 Tags and their meaning Tagging action is usually defined as a tripartite model Tagging(User, Resource, Tag) MOAT extends the model with the local meaning of a tag Tagging(User, Resource, Tag, Meaning) «In this tagging action paris refers to the french city» Yet, a tag can have different global meanings in a folksonomy space Meanings(Tag) = {(Meaning, {User})} 6

7 Modeling meanings, tags and tagging actions Defining meanings A need for machine-understandable meanings Using URIs of existing resources from LOD datasets paris» The MOAT Ontology - Modeling tags Tag class, extending the Tag Ontology, mappings with SCOT in progress Cardinality restriction regarding the name property (=1) Modeling global meanings of a tag hasmeaning property and TagMeaning class + meaninguri property Relies on FOAF for the user aspect - cardinality>=1 Modeling local meaning of a tag Based on the RestrictedTagging class fot the Tag Ontology tagmeaning property to define local meaning of a tag - cardinality=1 7

8 MOAT ontology diagram 8

9 MOAT data example < a moat:tag ; moat:name "paris" ; moat:hasmeaning [ a moat:meaning ; moat:meaninguri < ; foaf:maker < ] ; moat:hasmeaning [ a moat:meaning ; moat:meaninguri dbpedia:paris_hilton ; foaf:maker < ; foaf:maker < ]. 9

10 Creating Linked Data from tagging 10

11 The MOAT framework Goal: provide an easy way to create local and global meanings for tags A client-server approach People subscribe to a MOAT server and install a client on their tagging software When people create tagged content, client queries the server for tags meaning(s) and lets user define with new ones if needed A collaborative and decentralized approach Anyone can benefit from user-defined meanings in a community Needs only a few active users to be deployed Clients can be anywhere on the web, on any platform 11

12 The MOAT framework architecture 12

13 MOAT architecture principles REST-ful way to exchange between a server and clients Data exchanged between both is modeled in RDF Each tag URI on the MOAT server is dereferencable Uses content-negociation Provides direct access to RDF and json output Update tag description by sending an RDF file with TagMeaning instances to the server API key to restrict updates within a community 13

14 Current implementations MOAT Server Current implementation as a PHP5 application Can be plugged-in on any triple-store (ARC2, 3store bindings) Open-source MOAT Clients Drupal client, features Sindice interaction Helps users to find new URI if needed OpenLink Virtuoso 14

15 MOAT, Drupal and Sindice 15

16 New ways to interlink RDF data By linking tagged content to URIs, it provides new way to connect those contents Helps SIOC entering the Linked Data Web Since sioc provides a way to represent tagged content sioc:item and its subclasses sioc:topic property 16

17 Summary MOAT is about Offering an RDF model to define the meaning(s) of tags Providing a way to let tagged content enters the Linked Data Web Offering a framework to collaboratively achieve this goal MOAT is not about Automatic identification of URI from tag Automatic disambiguation of tags Ontology mining from tags but can provide an RDF model for such algorithms 17

18 Thank you! / Questions